Cameras for taking still photographs in digital form have become very popular. Most such cameras are operable in a manner similar to traditional film cameras, except that the pictures taken are stored in electronic form, such as on a compact flash removal media card.
Early digital cameras stored pictures in various electronic file formats depending upon the camera manufacturer. As digital cameras evolved, most began to store images in digital imaging formats that specify a main image and associated metadata. One example of such digital imaging formats is the now well-known Exchangeable Image File, or EXIF, format published by the Japan Electronic Industry Development Association. Version 2.1 of the EXIF standard is a current version and is publicly available via the Internet. The EXIF standard defines a format for storing a digital image comprising a main image and certain associated metadata. The metadata can include information such as a thumbnail, or miniature, representation of the main image and information about the main image itself, including the date, time, exposure setting, global positioning satellite location and other data. The metadata may be identified using certain “tags” or field names. For example, the “Compression” tag name is a field denoting whether an image is stored in a compressed format. Under the EXIF standard, a value of “6” in the Compression tag name indicates a compressed JPEG image.
After taking a picture with a digital still camera, consumers often want to view the picture on a display device such as a television. However, digital photos are commonly taken with the camera rotated away from its normal level orientation. As a result, the photo taken is correspondingly rotated, and the consumer is unable to view the picture in its original orientation without rotating the picture.
A picture stored in the digital imaging formats such as the EXIF format can be modified using personal computer software, but there are limitations. Such software can transform the main image portion of the EXIF image, which is typically stored within the EXIF file as an image in the Joint Photographic Experts Group, or JPEG, format. Current software, however, does not properly process the EXIF metadata. Thus, upon completion of the main image transformation, the software can store the transformed main image, but then either discards the metadata or merely stores a portion of the original metadata, which no longer accurately describes the now-transformed main image. For example, the main image and its corresponding metadata might be created while the camera is rotated by 90 degrees and stored in an EXIF file. Using a PC, existing software could read the EXIF file, extract the main image and transform it by rotating it to a level orientation for viewing. However, the thumbnail representation associated with the main image remains unchanged and still 90 degrees rotated from the now-transformed main image so that the thumbnail does not accurately portray the transformed image. The remaining metadata would likewise be inaccurate, such as regarding the height and width of the now-transformed main image. Consumers may attempt to view the transformed main image using the viewer software sold with the digital camera or to upload the transformed main image to a digital camera for later viewing. However, because the metadata no longer corresponds to the transformed main image, the software and the digital camera are unable to process the digital image, causing normal operation to cease. Moreover, a loss of the metadata may adversely affect categorizing and searching for images based on the metadata. In short, no satisfactory system or method exists to transform the main image of an EXIF image, to update the metadata to reflect the transformation and then to store the transformed main image along with the correspondingly updated metadata using the EXIF format.